Malicious PDF — malware analysis report

Static analysis result for SHA-256 28a6676d6fe6166d…

MALICIOUS

PDF

84.9 KB Created: 2021-01-03 18:40:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 7522494fedd3f2498aa1bffcb40837a9 SHA-1: e6bda5d542fbad17534b9de40be8f95742866760 SHA-256: 28a6676d6fe6166d41c89a23a2f7006c0b4a08020554b1e3663f99df3edcd260
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of embedded links, many pointing to disposable hosting services and a known malicious redirector. This behavior is indicative of a link farm designed to distribute malicious content or phish for information. The ClamAV detection and ML classifier further support its malicious nature. Although no scripts were explicitly extracted, the PDF structure and embedded links suggest an attempt to lure users to malicious sites, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://traffmen.ru/123?utm_term=comprehensive+rationality+vs+bounded+rationality
    • https://cdn.sqhk.co/werutojij/gficWhb/nofuzijuvalali.pdf
    • https://zomutelisofo.weebly.com/uploads/1/3/4/7/134712892/165314.pdf
    • https://dunogijejuj.weebly.com/uploads/1/3/0/8/130813547/pabuderukadon.pdf
    • https://cdn.sqhk.co/sisadenev/kIRIgiY/ralodeno.pdf
    • https://jafobepajimo.weebly.com/uploads/1/3/4/8/134881918/nuvamas.pdf
    • https://zibabesisem.weebly.com/uploads/1/3/4/6/134670176/lefepuzalox-sunofogim-nosalosivoji.pdf
    • https://cdn.sqhk.co/lewivapawo/dOpMhjd/ascension_sky_dragon_tips.pdf
    • https://ruzojewa.weebly.com/uploads/1/3/4/4/134437104/8299ec655d.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://uploads.strikinglycdn.com/files/43375768-ef8b-4a9e-ad84-74c44b07e270/watsons_go_to_birmingham_questions_and_answer.pdf
    • https://s3.amazonaws.com/xujitezu/16257713668.pdf
    • https://uploads.strikinglycdn.com/files/1c763d2f-9b5d-484f-bdbe-1d13baae2f46/89244136653.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e8f3.bin
7a02ac63152d03b1eecb34c44a980773440a250f2bfd1a3a8df3de97dca794de		 pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F3 5408 bytes
font_01_sfnt_off0000fb2a.bin
4225f0a0086f828aa91dc5bffe947821b98fc011d9f50e6f64a66d578cf6070e		 pdf-font-stream PDF embedded font (sfnt) at offset 0xFB2A 11788 bytes
font_02_sfnt_off00012396.bin
23e5e0a6ad5360bf10628433507e5aab34c42d7d900ccb2a5214949f2168b422		 pdf-font-stream PDF embedded font (sfnt) at offset 0x12396 16112 bytes
font_03_sfnt_off00013866.bin
4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3		 pdf-font-stream PDF embedded font (sfnt) at offset 0x13866 4324 bytes

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